Fuel nozzle and swirler

ABSTRACT

An engine can utilize a combustor to combust fuel to drive the engine. A fuel nozzle assembly can supply fuel to the combustor for combustion or ignition of the fuel. The fuel nozzle assembly can include a swirler and a fuel nozzle to supply a mixture of fuel and air for combustion. The fuel nozzle assembly can be configured to increase lateral provision of fuels to reduce flame scrubbing on combustor liners for the combustor.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 63/294,620, filed Dec. 29, 2021, the entirety ofwhich is incorporated herein by reference.

FIELD

The present subject matter relates generally to a combustor for aturbine engine, the combustor having one or both of a fuel nozzle and aswirler.

BACKGROUND

An engine, such as a turbine engine, can include a turbine or otherfeature that is driven by combustion of a combustible fuel within acombustor of the engine. The engine utilizes a fuel nozzle to inject thecombustible fuel into the combustor. A swirler provides for mixing thefuel with air in order to achieve efficient combustion.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present disclosure, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 is a schematic cross-sectional view of an engine in accordancewith an exemplary embodiment of the present disclosure.

FIG. 2 is a schematic cross-sectional view of a combustor for the engineof FIG. 1 in accordance with an exemplary embodiment of the presentdisclosure.

FIG. 3 is a cross-sectional view of a fuel nozzle assembly with a fuelnozzle including a nozzle cap, and a swirler having a splitter inaccordance with an exemplary embodiment of the present disclosure.

FIG. 4 is a cross-sectional view of the nozzle cap of FIG. 3 , takenacross section IV-IV of FIG. 3 , looking forward at the nozzle cap inaccordance with an exemplary embodiment of the present disclosure.

FIG. 5 is a view of an alternative nozzle cap for a fuel nozzle inaccordance with an exemplary embodiment of the present disclosure.

FIG. 6 is a view of an alternative fuel nozzle assembly, showing anexemplary nozzle cap for a fuel nozzle provided within a swirler inaccordance with an exemplary embodiment of the present disclosure.

FIG. 7 is a view of an exemplary combustor illustrating two arrangedfuel nozzle assemblies of FIG. 6 in accordance with an exemplaryembodiment of the present disclosure.

FIG. 8 is a view of another exemplary combustor illustrating an angularoffset for fuel nozzles relative to the circumferential arrangement ofthe combustor in accordance with an exemplary embodiment of the presentdisclosure.

FIG. 9 is a view of another exemplary combustor illustrating a radialoffset for fuel nozzles relative to the circumferential arrangement ofthe combustor in accordance with an exemplary embodiment of the presentdisclosure.

FIG. 10 is a view of another exemplary combustor illustrating an angularoffset for one fuel nozzle, while another fuel nozzle includes noangular offset in accordance with an exemplary embodiment of the presentdisclosure.

FIG. 11 is a view of another exemplary fuel nozzle assembly with aracetrack-shaped nozzle cap and elliptical swirler passage in accordancewith an exemplary embodiment of the present disclosure.

FIG. 12 is a view of yet another exemplary fuel nozzle assembly with aracetrack-shaped nozzle cap and racetrack-shaped swirler passage inaccordance with an exemplary embodiment of the present disclosure.

FIG. 13 is a view of a circular cap for a fuel nozzle including openingsarranged in elliptical sets in accordance with an exemplary embodimentof the present disclosure.

FIG. 14 is a view of another circular cap for a fuel nozzle includingopenings arranged in circular sets, with varying cross-sectional areasfor the openings in accordance with an exemplary embodiment of thepresent disclosure.

FIG. 15 is a view of yet another circular cap for a fuel nozzleincluding openings arranged in elliptical sets, with varyingcross-sectional areas for the openings in accordance with an exemplaryembodiment of the present disclosure.

FIG. 16 is a flow chart showing a method injecting fuel from a fuelnozzle assembly in accordance with an exemplary embodiment of thepresent disclosure,

DETAILED DESCRIPTION

Aspects of the disclosure herein are directed to a fuel nozzle andswirler architecture located within an engine component, and morespecifically to a fuel nozzle structure, nozzle cap structure, orswirler structure configured for use with heightened combustion enginetemperatures, such as those utilizing a hydrogen fuel of hydrogen fuelmixtures. Higher temperature fuels like hydrogen fuels can reduce oreliminate carbon and NOx emissions, but generate challenges relating toflame holding or flashback due to the higher flame speed andhigh-temperatures. Current combustors include a durability risk whenusing such high-temperature fuels due to flame holding or flashback oncombustor components when using such fuels. For purposes ofillustration, the present disclosure will be described with respect to aturbine engine for an aircraft with a combustor driving the turbine. Itwill be understood, however, that aspects of the disclosure herein arenot so limited, and can have additional applicability in othercommercial, residential, or industrial applications.

During combustion, the engine generates high local temperatures.Efficiency and carbon emission needs require fuels that burn hotter thantraditional fuels, or that reduced carbon emissions require the use offuels with higher burn temperatures, like hydrogen fuel. For example,burn temperatures and burn speeds can be higher than that of currentengine fuels, such that existing engine designs would include durabilityrisks operating with such fuels or under the heightened temperaturesrequired for heightened efficiency and emission standards.

Reference will now be made in detail to the fuel nozzle and swirlerarchitecture, one or more examples of which are illustrated in theaccompanying drawings. The detailed description uses numerical andletter designations to refer to features in the drawings. Like orsimilar designations in the drawings and description have been used torefer to like or similar parts of the disclosure.

The word “exemplary” is used herein to mean “serving as an example,instance, or illustration.” Any implementation described herein as“exemplary” is not necessarily to be construed as preferred oradvantageous over other implementations. Additionally, unlessspecifically identified otherwise, all embodiments described hereinshould be considered exemplary.

The terms “forward” and “aft” refer to relative positions within aturbine engine or vehicle, and refer to the normal operational attitudeof the turbine engine or vehicle. For example, with regard to a turbineengine, forward refers to a position closer to an engine inlet and aftrefers to a position closer to an engine nozzle or exhaust.

As used herein, the term “upstream” refers to a direction that isopposite the fluid flow direction, and the term “downstream” refers to adirection that is in the same direction as the fluid flow. The term“fore” or “forward” means in front of something and “aft” or “rearward”means behind something. For example, when used in terms of fluid flow,fore/forward can mean upstream and aft/rearward can mean downstream.

The term “fluid” may be a gas or a liquid. The term “fluidcommunication” means that a fluid is capable of making the connectionbetween the areas specified.

The terms “forward” and “aft” refer to relative positions within aturbine engine or vehicle, and refer to the normal operational attitudeof the turbine engine or vehicle. For example, with regard to a turbineengine, forward refers to a position closer to an engine inlet and aftrefers to a position closer to an engine nozzle or exhaust.

The term “flame holding” relates to the condition of continuouscombustion of a fuel such that a flame is maintained along or near to acomponent, and usually a portion of the fuel nozzle assembly asdescribed herein, and “flashback” relate to a retrogression of thecombustion flame in the upstream direction. The term “flame scrubbing”relates to the condition of the combusted flame brushing against theinner or outer combustor liner, or other component.

Additionally, as used herein, the terms “radial” or “radially” refer toa direction away from a common center. For example, in the overallcontext of a turbine engine, radial refers to a direction along a rayextending between a center longitudinal axis of the engine and an outerengine circumference.

All directional references (e.g., radial, axial, proximal, distal,upper, lower, upward, downward, left, right, front, back, top, bottom,above, below, vertical, horizontal, clockwise, counterclockwise,upstream, downstream, forward, aft, etc.) are only used foridentification purposes to aid the reader's understanding of the presentdisclosure, and do not create limitations, particularly as to theposition, orientation, or use of aspects of the disclosure describedherein. The term ‘lateral’ as used herein can represent a sidewaysdirection, relative to an upward or downward direction, or relative to aradial direction. More specifically, a lateral direction as used hereincan represent a direction tangent to the circumference of the element, adirection perpendicular to a radius extending from a central orlongitudinal axis, or in a circumferential direction, where a lateraldirection includes a curved geometry to account for the annulararrangement of the fuel nozzle assembly, combustor section, or enginediscussed herein. For example, the lateral direction can be tangent tothe circumferential direction defined by the annular combustor. Inanother example, the lateral direction can be tangent to thecircumferential direction defined by the annular fuel nozzle assembly,fuel nozzle, or swirler. Connection references (e.g., attached, coupled,connected, and joined) are to be construed broadly and can includeintermediate structural elements between a collection of elements andrelative movement between elements unless otherwise indicated. As such,connection references do not necessarily infer that two elements aredirectly connected and in fixed relation to one another. The exemplarydrawings are for purposes of illustration only and the dimensions,positions, order and relative sizes reflected in the drawings attachedhereto can vary.

The singular forms “a”, “an”, and “the” include plural references unlessthe context clearly dictates otherwise. Furthermore, as used herein, theterm “set” or a “set” of elements can be any number of elements,including only one.

Approximating language, as used herein throughout the specification andclaims, is applied to modify any quantitative representation that couldpermissibly vary without resulting in a change in the basic function towhich it is related. Accordingly, a value modified by a term or terms,such as “about”, “approximately”, “generally”, and “substantially”, arenot to be limited to the precise value specified. In at least someinstances, the approximating language may correspond to the precision ofan instrument for measuring the value, or the precision of the methodsor machines for constructing or manufacturing the components and/orsystems. For example, the approximating language may refer to beingwithin a 1, 2, 4, 5, 10, 15, or 20 percent margin in either individualvalues, range(s) of values and/or endpoints defining range(s) of values.Here and throughout the specification and claims, range limitations arecombined and interchanged, such ranges are identified and include allthe sub-ranges contained therein unless context or language indicatesotherwise. For example, all ranges disclosed herein are inclusive of theendpoints, and the endpoints are independently combinable with eachother.

The combustor introduces fuel from a fuel nozzle, which is mixed withair provided by a swirler, and then combusted within the combustor todrive the engine. Increases in efficiency and reduction in emissionshave driven the need to use fuel that burns cleaner or at highertemperatures. There is a need to improve durability of the combustorunder these operating parameters, such as improved flame control toprevent flame holding on the fuel nozzle and swirler components.

FIG. 1 is a schematic view of an engine as an exemplary turbine engine10. As a non-limiting example, the turbine engine 10 can be used withinan aircraft. The turbine engine 10 can include, at least, a compressorsection 12, a combustion section 14, and a turbine section 16. A driveshaft 18 rotationally couples the compressor and turbine sections 12,16, such that rotation of one affects the rotation of the other, anddefines a rotational axis 20 for the turbine engine 10.

The compressor section 12 can include a low-pressure (LP) compressor 22,and a high-pressure (HP) compressor 24 serially fluidly coupled to oneanother. The turbine section 16 can include an LP turbine 28, and an HPturbine 26 serially, fluidly coupled to one another. The drive shaft 18can operatively couple the LP compressor 22, the HP compressor 24, theLP turbine 28 and the HP turbine 26 together. Alternatively, the driveshaft 18 can include an LP drive shaft (not illustrated) and an HP driveshaft (not illustrated). The LP drive shaft can couple the LP compressor22 to the LP turbine 28, and the HP drive shaft can couple the HPcompressor 24 to the HP turbine 26. An LP spool can be defined as thecombination of the LP compressor 22, the LP turbine 28, and the LP driveshaft such that the rotation of the LP turbine 28 can apply a drivingforce to the LP drive shaft, which in turn can rotate the LP compressor22. An HP spool can be defined as the combination of the HP compressor24, the HP turbine 26, and the HP drive shaft such that the rotation ofthe HP turbine 26 can apply a driving force to the HP drive shaft whichin turn can rotate the HP compressor 24.

The compressor section 12 can include a plurality of axially spacedstages. Each stage includes a set of circumferentially-spaced rotatingblades and a set of circumferentially-spaced stationary vanes. Thecompressor blades for a stage of the compressor section 12 can bemounted to a disk, which is mounted to the drive shaft 18. Each set ofblades for a given stage can have its own disk. The vanes of thecompressor section 12 can be mounted to a casing which can extendcircumferentially about the turbine engine 10. It will be appreciatedthat the representation of the compressor section 12 is merely schematicand that there can be any number of stages. Further, it is contemplated,that there can be any other number of components within the compressorsection 12.

Similar to the compressor section 12, the turbine section 16 can includea plurality of axially spaced stages, with each stage having a set ofcircumferentially-spaced, rotating blades and a set ofcircumferentially-spaced, stationary vanes. The turbine blades for astage of the turbine section 16 can be mounted to a disk which ismounted to the drive shaft 18. Each set of blades for a given stage canhave its own disk. The vanes of the turbine section can be mounted tothe casing in a circumferential manner. It is noted that there can beany number of blades, vanes and turbine stages as the illustratedturbine section is merely a schematic representation. Further, it iscontemplated, that there can be any other number of components withinthe turbine section 16.

The combustion section 14 can be provided serially between thecompressor section 12 and the turbine section 16. The combustion section14 can be fluidly coupled to at least a portion of the compressorsection 12 and the turbine section 16 such that the combustion section14 at least partially fluidly couples the compressor section 12 to theturbine section 16. As a non-limiting example, the combustion section 14can be fluidly coupled to the HP compressor 24 at an upstream end of thecombustion section 14 and to the HP turbine 26 at a downstream end ofthe combustion section 14.

During operation of the turbine engine 10, ambient or atmospheric air isdrawn into the compressor section 12 via a fan (not illustrated)upstream of the compressor section 12, where the air is compresseddefining a pressurized air. The pressurized air can then flow into thecombustion section 14 where the pressurized air is mixed with fuel andignited, thereby generating combustion gases. Some work is extractedfrom these combustion gases by the HP turbine 26, which drives the HPcompressor 24. The combustion gases are discharged into the LP turbine28, which extracts additional work to drive the LP compressor 22, andthe exhaust gas is ultimately discharged from the turbine engine 10 viaan exhaust section (not illustrated) downstream of the turbine section16. The driving of the LP turbine 28 drives the LP spool to rotate thefan (not illustrated) and the LP compressor 22. The pressurized airflowand the combustion gases can together define a working airflow thatflows through the fan, compressor section 12, combustion section 14, andturbine section 16 of the turbine engine 10.

FIG. 2 depicts a cross-section view of a combustor 36 suitable for usein the combustion section 14 of FIG. 1 . The combustor 36 can include anannular arrangement of fuel nozzle assemblies 38 for providing fuel tothe combustor 36. It should be appreciated that the fuel nozzleassemblies 38 can be organized as in an annular arrangement includingmultiple fuel injectors. The combustor 36 can have a can, can-annular,or annular arrangement depending on the type of engine in which thecombustor 36 is located. The combustor 36 can include an annular innercombustor liner 40 and an annular outer combustor liner 42, a domeassembly 44 including a dome 46 and a deflector 48, which collectivelydefine a combustion chamber 50 about a longitudinal axis 52. At leastone fuel injector 54 is fluidly coupled to the combustion chamber 50 tosupply fuel to the combustor 36. The fuel injector 54 can be disposedwithin the dome assembly 44 upstream of a flare cone 56 to define a fueloutlet 58. A swirler can be provided with the fuel nozzle assembly 38 toswirl incoming air in proximity to fuel exiting the fuel injector 54 andprovide a homogeneous mixture of air and fuel entering the combustor 36.

FIG. 3 illustrates a fuel nozzle assembly 130, suitable for use in thecombustor 36 as the fuel nozzle assembly 38 of FIG. 2 , including a fuelnozzle 132, defining a longitudinal axis 128, and a swirler 134circumscribing the fuel nozzle 132. The fuel nozzle 132 can provide asupply of fuel in a generally axial direction, while the swirler 134 canprovide a swirling air flow in the axial direction with the air flowincludes a tangential component to define the swirl. The air flowintroduced to the swirler 134 can be from the radial or the axialdirection, in non-limiting examples. The fuel nozzle 132 can define afuel passage 136, with a nozzle cap 138 provided in the fuel passage 136upstream of a nozzle tip 139. The swirler 134 includes a forward wall140 and an aft wall 142, with a set of vanes 144 extending between theforward wall 140 and the aft wall 142. The vanes 144 can be provided atan angle, in order to impart a tangential component, or swirl component,to airflow passing through the swirler 134. A central wall 146 canseparate the swirler 134 into a forward passage 148 and an aft passage150, and the vanes 144 can be arranged as two sets of vanes within eachof the forward passage 148 and the aft passage 150. A splitter 152extends aft of the central wall 146 from the vanes 144. A swirlerpassage 162, downstream of the vanes 144, can be separated into aradially exterior passage 168 and a radially interior passage 170.

FIG. 4 shows a view of the fuel nozzle assembly 130, taken along sectionIV-IV of FIG. 3 . The fuel nozzle 132 includes an exterior wall 160. Theexterior wall 160 can include a circular or elliptical cross-sectionalshape, as shown, including a lateral axis 154 extending in the lateraldirection, and a transverse axis 156, perpendicular to the lateral axis154. Additional shapes are contemplated, such as an oval, a stadium ordiscorectangle, or other curvilinear geometries in non-limitingexamples. The lateral axis 154 can be aligned with a major axis definedby the elliptical shape of the fuel nozzle 132. More specifically, it iscontemplated that the major axis can extend in the lateral direction,extending from the center of the ellipse, or alternatively can beextending from any point on the ellipse, such that the major axis isdefined in the lateral direction, or parallel thereto, and the minoraxis is defined perpendicular to the lateral direction, or along thetransverse axis 156. Furthermore, the transverse axis 156 can be alignedwith a ray extending from a longitudinal axis defined by the combustorsection, a ray extending from a longitudinal axis defined by the fuelnozzle assembly 130, or a ray extending from the engine centerline.Additionally, it is contemplated that lateral axis 154 can be alignedtangent to a radius extending from a longitudinal axis defined by theengine centerline, the combustor section, or the fuel nozzle assembly130.

A nozzle cap 138 is provided within the fuel nozzle 132. A set ofopenings 166 are provided in the nozzle cap 138. The nozzle openings 166can be separated into radially exterior openings 166 a and radiallyinterior openings 166 b, relative to a central opening 166 c of the fuelnozzle cap 138. The radially exterior openings 166 a can include a majoraxis that is parallel to the major axis defined by the nozzle cap 138.The radially exterior openings 166 a and the radially interior openings166 b can include a circular or elliptical cross-sectional shape, whileany cross-sectional shape is contemplated. It should be appreciated thatthe arrangement as shown is exemplary, and that different arrangementsor shapes are contemplated, such as including more or less openings orother arrangements thereof.

The elliptical shape for the fuel nozzle 132 and the radially exterioropenings 166 a creates a higher concentration and downstream spread offuel in the lateral direction, relative to the fuel nozzle 132, wherethe lateral direction can be defined in the circumferential directionrelative to the engine centerline, or with respect to the annularcombustor, or can be defined perpendicular to both the radial directionand the axial direction. In one example, the fuel nozzle 132, nozzle cap138, or the openings 166 can define a total area, which can be a totalcross-sectional area defined in the radial direction relative to thelongitudinal axis 128 (illustrated as an “X”, as the axis extends intoand out of the page in FIG. 4 ) or the engine rotational axis 20 of FIG.1 . The elliptical or other non-circular shape can define provide adistribution of the total area where a greater amount of fuel isdistributed along the lateral axis 154, and a comparatively lesseramount of fuel along the transverse axis 156. The nozzle openings 166can collectively define a total area, and the arrangement of the nozzlecap 138 and the openings 166 arrange a greater amount of the total areaalong the lateral axis 154 and a relatively lesser amount along thetransverse axis 156, or extending in a direction along the transverseaxis 156, away from the lateral axis 154. This arrangement distributes agreater amount of fuel in the lateral direction along the lateral axis154, which provides for a higher concentration of fuel in thecircumferential direction about a combustor centerline, and a lesserconcentration of fuel in the radial direction toward the combustorliners. Higher lateral concentrations and increased lateral spread ofthe fuel supply creates a relatively smaller concentration and decreasedfuel spread in the radial or vertical direction, along the transverseaxis 156, which can reduce flame scrubbing on the combustor linerdownstream of the fuel nozzle assembly 130. Reduced flame scrubbingprovides for improved durability for the liner, which permits the use ofhigher temperature fuels, such as hydrogen or hydrogen mixes innon-limiting examples, which can provide for reduce or eliminated carbonemissions or NOx emissions. Furthermore, reduced flame scrubbing canprovide for reduced cooling requirements, which can improve coolingefficiency for the engine. The lateral orientation for the fuel nozzles132 and the radially exterior openings 166 a further improves cut-to-cupinteraction, which can permit reduction of cup count, reducing enginecomplexity and weight.

Furthermore, a swirler passage 162 from the swirler 134, radiallyexterior of the exterior wall 160, can be circumferentially varied. Thiscircumferential area variation can be done by utilizing differing shapesbetween the fuel nozzle 132 and the swirler 134, such as utilizing anelliptical fuel nozzle 132 with an elliptical swirler 134, defining adifferent ellipse than that of the fuel nozzle 132, to define a varyingradial distance R between the two. The varying area in swirler passage162 can change the velocity profile on the exterior wall 160 of fuelnozzle 132. The circumferential area variation can be such that largergap is present in the lateral direction or along the lateral axis 154,and a relatively smaller gap is present in the vertical direction, oralong the transverse axis 156. A larger gap creates a lower air momentumand allows fuel to penetrate more in the lateral direction, whereas alarger gap creates higher air momentum, resisting vertical fuelpenetration. Higher air flow and less fuel penetration in the verticaldirection helps to prevent high temperatures or flame scrubbing on thecombustor liner wall. Higher fuel flow and high fuel penetration inlateral direction helps for better cup-to-cup flow interaction and allowcup count reduction. Increased lateral fuel provision can reduce cupcount, which is a reduction in the number of fuel nozzle assemblies forthe combustor, which reduces engine cost, complexity, and weight.Furthermore, the lateral fuel provision provides for increased cupspacing, without negative impact to flame propagation within thecombustor.

FIG. 5 illustrates an alternative fuel nozzle cap 200, defining alateral axis 210 and a transverse axis 212, and including a set ofopenings 202. The openings 202 can be arranged as an exterior set ofopenings 202 a, an interior set of openings 202 b, and a central opening202 c. The exterior openings 202 a can include a circular or ellipticalcross-sectional shape, for example, with a major axis arranged in thevertical or radial direction, parallel to the lateral axis 210.Furthermore, the exterior openings 202 a can vary in cross-sectionalarea, such that the area increases extending in the lateral directionalong the lateral axis 210, relative to the central opening 202 c.Additionally, the exterior openings 202 a can vary in cross-sectionalshape, such that the exterior openings 202 a have a circularcross-sectional at a radial top 204 and a radial bottom 206, along thetransverse axis 212.

The interior set of openings 202 b can include a circular cross-sectionand a common cross-sectional area, while alternative shapes, sizes,orientations, patterns, or arrangements are contemplated. Additionally,the cross-sectional area and shape of the central opening 202 c can bethe same as that of the interior set of openings 202 b, while variationamong the two is contemplated.

An outer wall 208 can define the shape of the fuel nozzle cap 200. Thecross-sectional shape of the fuel nozzle cap 200 can be elliptical, witha major axis arranged in the along the lateral axis 210. Utilizing anelliptical shape for the nozzle cap 200 provides for limiting the radialextent of the fuel supplied through the fuel nozzle cap 200.Additionally, the elliptical shape for the nozzle cap 200 can providefor limiting the radial spread of fuel supplied by the radialorientation of the major axes of the exterior openings 202 a. That is,the shape of the nozzle cap 200 limits the radial spread of fuelsupplied by the exterior openings 202 a, such that fuel is consistentlyspread by the exterior openings 202 a, maintained within the radiallimits defined by the shape of the nozzle cap 200.

Furthermore, the variation of the cross-sectional area of the exterioropenings 202 a provides for increased flow volumes in the lateraldirection with decreased relative flow volumes in the radial direction.As the openings 202 a in the lateral or circumferential direction have alarger cross-sectional area, which can provide increase fuel in thelateral direction, with lesser cross-sectional area openings providingfuel in the radial direction, which can maintain the flame radiallywithin the combustor to reduce flame scrubbing on the combustor liners.

Referring to FIG. 6 , another alternative fuel nozzle 230 including anouter wall 232 and a nozzle cap 234 defining a lateral axis 248 and atransverse axis 250. A set of openings 236 are provided in the nozzlecap 234, which can be arranged into an outer set of openings 236 a, aninner set of openings 236 b, and a central opening 236 c. Similar tothat of FIG. 5 , the exterior openings 236 a can have an increasingcross-sectional area extending in the lateral direction, and adecreasing cross-sectional area extending in the radial direction. Theradially exterior-most and interior-most outer openings 236 a caninclude an elliptical cross-sectional shape with the major axis definedin the lateral direction, such that the fuel emitted from the radiallyinner-most and outer-most openings 236 a of the fuel nozzle 230 spreadsin the lateral direction, which limits the radial spread of fuel withinthe combustor to reduce flame scrubbing on the combustor liner.

An annular swirler passage 238 can be defined between a swirler outerwall 239 and the fuel nozzle outer wall 232. The cross-sectional area ofthe swirler passage 238 can vary, similar to that of the exterior wall160 for the fuel nozzle of FIG. 4 , having an increasing cross-sectionalarea extending in the radially outward and inward direction, along thetransverse axis 250, relative to the central opening 236 c, while havinga decreasing cross-sectional area in the circumferential direction,relative to the central opening 236 c. The greater cross-sectional areaat the radial extents provides for greater swirler flow volume, whichimproves radial containment of the flame, which further reduces flamescrubbing on the combustor liner and also improves lateral spread of thefuel from the fuel nozzle.

It is further contemplated that the outer wall 232 can include a varyingcross-sectional area, or thickness defined in the radial direction,similar to that of the annular swirler passage 238. The cross-sectionalarea can increase in a direction along the transverse axis 250, whiledecreasing in a direction along the lateral axis 248, away from thetransverse axis 250. In this way, the varying cross-sectional shape forthe outer wall 232 can be used to vary the cross-sectional shape betweenthe nozzle cap 234 and the swirler passage 238, such that a variation inshape between the swirler passage 238 and the nozzle cap 234, or fuelnozzle passage, can be achieved. Such variation permits greater controlof lateral provision of both the fuel and the airflow provided from theswirler, which can be varied independent of one another via the outerwall 232.

FIG. 7 shows a portion of a circumferential combustor 240, looking inthe forward direction at two of the set of fuel nozzles 230 of FIG. 6 .The nozzles 230 are provided on a deflector 242 between an outer liner244 and an inner liner 246. The shaping of the fuel nozzle 230 and theswirler passage 238 can provide improved radial flame control, whichreduces flame scrubbing on the outer and inner liners 244, 246.Furthermore, the improved radial flame control provides for increasedfuel nozzle spacing, which reduces the number of required fuel nozzles230 for a combustor, which reduces overall system weight and complexity.

FIG. 8 shows a portion of another circumferential combustor 260, lookingin the forward direction at two fuel nozzles 262 provided on a deflectorwall 264 between an outer liner 266 and an inner liner 268. Each of thefuel nozzles 262 can be similar, including an elliptical cross-sectionalshape defining a major axis 270. A tangential axis 272 can be definedfor each fuel nozzle 262, where the tangential axis 272 is definedtangent to the circumferential direction, where the circumferentialdirection is defined by the engine rotational axis 20 of FIG. 1 , or theannular combustor 260. The tangential axis 272 can extend in thetangential direction from the center of the fuel nozzles 262, at acentral opening 274. An offset angle 276 can be defined as the anglebetween the tangential axis 272 and the major axis 270 for each fuelnozzle 262. The offset angle 276 can be between 0-degrees and90-degrees, where 0-degrees represents an alignment between the majorand tangential axes 270, 272 and 90-degrees represent an orthogonaloffset such that the major axis 270 is aligned with the radialdirection.

It is further contemplated that a subset of fuel nozzles 262 can bearranged at the offset angle 276, such as every other fuel nozzle 262 isarranged at the offset angle 276, and the other fuel nozzles 262 are notarranged at the offset angle 276. In another example, a first subset offuel nozzles 262 can be arranged at a first offset angle 276, while asecond subset of fuel nozzles can be arranged at a second offset angle,different than the first offset angle 276.

It should be appreciated that utilizing the angular offset can providefor increasing fuel spread as compared to having lesser or no angularoffset. Furthermore, the offset can help account for the swirling flowwithin the combustor, such as reducing turbulence or shear relative tothe tangential flow component.

FIG. 9 shows a portion of another circumferential combustor 300, lookingin the forward direction at two fuel nozzles 302 provided on a deflectorwall 304 between an outer liner 306 and an inner liner 308. A first fuelnozzle 310 and a second fuel nozzle 312 can each include an ellipticalshape defining a major axis. The major axis of the first fuel nozzle 310can be arranged tangent to a first circumferential axis 314 and themajor axis of the second fuel nozzle 312 can be arranged tangent to asecond circumferential axis 316. The first and second circumferentialaxes 314, 316 can be offset in the radial direction. It should beappreciated that a set of fuel nozzles 302 can be provided in an annulararrangement about the combustor 300, and the set of fuel nozzles 302 canbe separated into two subsets, with each subset aligned with either thefirst or second circumferential axes 314, 316. In this way, the fuelnozzles 302 can be staggered, which can be utilized to further increasespacing between fuel nozzles, or can be used to break combustiondynamics otherwise generated by a combustor without such staggering.

It should be further contemplated that the circumferential offsetdescribed in FIG. 9 can be combined with the angular offset of FIG. 8 .For example, a set of fuel nozzles can includes a first subset alignedat a first circumferential axis, and arranged at a first offset angle,and a second subset is aligned with a second circumferential axis,spaced from the first circumferential axis, and arranged at a secondoffset angle, different than the first offset angle.

Further still, referring to FIG. 10 showing another exemplary combustor320, where each fuel nozzle 322 can be discretely arranged, such as atan angular offset, or a circumferential stagger, or combination thereof.Such arrangements can be defined about the annular combustor 320, suchas every-other fuel nozzle 322 a includes an angular offset, while everyother fuel nozzle 322 b does not, or that every other fuel nozzle 322 bis arranged different than the first fuel nozzle 322 a. Such patternscan be used to centrally-maintain the fuel distribution, whilepermitting increased flame control or shaping among a circumferentialcombustor, while providing for limited fuel spread in the radialdirection, which can provide for reducing or eliminating flame scrubbingalong the liners while permitting the use of higher temperature and burnspeed fuels to reduce emissions and maintain efficiency.

FIG. 11 shows an exemplary, schematic cross-sectional view of a fuelnozzle assembly 350, defining a lateral axis 366 and a transverse axis368, and including a fuel nozzle 352 circumscribed by a swirler passage354 defined between a swirler wall 356 of a swirler 358 and an outersurface 360 of the fuel nozzle 352. The outer surface 360 can have across-sectional shape that is a racetrack shape, including linear sides362 extending between curved ends 364, while additional shapes arecontemplated. The swirler wall 356 can include an elliptical shape, witha major axis arranged parallel with the linear sides 362 of the fuelnozzle 352.

The differences in shape between the swirler 358 and the fuel nozzle 352can be used to affect the local velocity, where a greatercross-sectional spacing between the swirler 358 and the fuel nozzle 352can generate a lower fuel-and-air mixture, while lesser spacing betweenthe swirler 358 and the fuel nozzle 352 can generate a greater mixturebetween the fuel and air, particularly in the lateral direction alongthe lateral axis 366, which can be utilized to limit the radial spreadof the fuel, which provides for reducing flame scrubbing on the liner.In this way, it should be appreciated that the geometry of the swirler358 can be utilized to define the local mixture between the fuel and theair, which can be utilized to control the flame shape or flame spreadprovided in the combustor, also decreasing flame scrubbing on theliners.

FIG. 12 shows an alternative cross-sectional shape for a fuel nozzleassembly 380, defining a lateral axis 390 and a transverse axis 392, andincludes a fuel nozzle 382 having a race track shape. A swirler passage384 is defined between the fuel nozzle 382 and an outer wall 386 of aswirler 388. The outer wall 386 of the swirler 388 can beracetrack-shaped, being complementary to the shape of the fuel nozzle382, such that a uniform cross-sectional distance is maintained for theentire swirler passage 384. In this way, it should be appreciated thatthe cross-sectional distance appears non-uniform as shown, while itshould be understood that identical shapes are contemplated to define aconstant distance around the entirety of the fuel nozzle 382.

FIG. 13 is a cross section of another exemplary fuel nozzle cap 400. Thefuel nozzle cap 400 can be circular, defining a lateral axis 404 and atransverse axis 406, and includes a set of openings 402. The set ofopenings 402 can be arranged into annular rows or sets, visuallyidentified by the curved broken lines, as an outer set of openings 402a, an inner set of openings 402 b, and a central opening 402 c. Theouter and inner openings 402 a, 402 b can be arranged in an ellipticalarrangement, such that a major axis is defined in the lateral directionalong the lateral axis 404. The openings 402 a-b provided in anelliptical arrangement can provide for increased lateral provision offuel, which can reduce flame scrubbing along the liners, as well asreduce the required number of fuel nozzles.

FIG. 14 is another cross section of another exemplary fuel nozzle cap420. The fuel nozzle cap 420 can be circular, defining a lateral axis430 and a transverse axis 432, including a set of openings 422. The setof openings 422 can be arranged into annular rows, visually identifiedby the curved broken lines, as an outer set of openings 422 a, an innerset of openings 422 b, and a central opening 422 c. The outer and innersets of openings 422 a, 422 b can include an increased cross-sectionalarea for the openings 422 a nearer to the lateral sides 424, or alongthe lateral axis 430, relative to the openings 422 a, 422 b nearer to aradial top 426 or a radial bottom 428, or arranged along the transverseaxis 432. While the fuel nozzle cap 420 is circular, the increasingcross-sectional area for the openings moving in the lateral directioncan provide for greater lateral provision of fuel, which can providebetter radial flame control for the combustor, which can reduce flamescrubbing along the liner and reduce the number of required fuelnozzles.

FIG. 15 is another cross section of another exemplary fuel nozzle cap440, defining a lateral axis 444 and a transverse axis 446, includingopenings 442 arranged into an outer circumferential row of openings 442a and an inner circumferential row of openings 442 b. The nozzle cap 440can be circular, while the rows of openings 442 a, 442 b can be arrangedin an elliptical arrangement, similar to that of FIG. 13 , andincreasing cross-sectional area for the rows of openings 442 a, 442 b inthe lateral direction, similar to that of FIG. 14 .

Referring now to FIG. 16 , a method 500 for injecting fuel from a fuelnozzle assembly is provided. The fuel nozzle assembly for the method 500can be any fuel nozzle assembly as described herein such as any of thefuel nozzle assemblies 130, 350, 380, and can include a fuel nozzle thatdefines a lateral axis and a transverse axis, such as fuel nozzles 132,230, 262, 302, 322, 352, 382.

At 502, the method 500 can include injecting fuel through a nozzle cap,by injecting fuel through openings provided in the nozzle cap, such asthat described herein, including the nozzle caps 138, 200, 234, 400,420, 440 as described herein. The nozzle cap can define a total area,which can be defined as the cross-sectional area for the fuel nozzle.

At 504, the method 500 can further include spreading fuel in a lateraldirection. Spreading fuel in the lateral direction can be accomplishedby any means described herein. For example, a fuel nozzle or a nozzlecap, defining a lateral axis and a transverse axis, can be shaped suchthat a greater amount of the total area of the fuel nozzle or nozzle capis provided along the lateral axis than the transverse axis, similar tothat of FIGS. 4-6 and 11-12 . In another example, the set of openingscan further define a total area, as the collective cross-sectional areaof all of the openings in the set of openings. A greater amount of thetotal area of the set of openings can be arranged closer to the lateralaxis than the transverse axis, such as that of FIGS. 5-6 and 14-15 .Such an arrangement of the nozzle cap, or the openings therein, providesfor spreading a greater amount of fuel along the lateral axis and alesser amount along the transverse axis.

In another example, the nozzle cap can define a non-circular shape, suchthat a major axis, or greatest diameter, is different from a minor axis,or least diameter. Arranging the major axis for the nozzle cap along thelateral axis provides for spreading a greater amount of fuel along thelateral axis. In yet another example, the set of openings can bearranged in an elliptical pattern, such that the arrangement defines amajor axis along the lateral axis, providing a greater amount of fuelalong the lateral axis as opposed to along the transverse axis, whichcan align with a minor axis defined by the elliptical arrangement of theset of openings, such as that of FIGS. 13 and 15 .

The method 500 distributes a greater amount of fuel along the lateralaxis defined by the nozzle cap or the openings therein, which providesfor a higher concentration of fuel in the circumferential directionabout a combustor centerline or engine rotational axis, and a lesserconcentration of fuel in the radial direction, relative thereto. Higherlateral concentrations and increased lateral spread of the fuel supplycreates a relatively smaller concentration and decreased fuel spread inthe radial or vertical direction, which reduces flame scrubbing on thecombustor liners. Reduced flame scrubbing provides for improveddurability for the liner, which permits the use of higher temperaturefuels, such as hydrogen or hydrogen mixtures, which reduce or eliminatecarbon emissions or NOx emissions. Furthermore, reduced flame scrubbingcan provide for reduced cooling requirements, which can improve coolingefficiency for the engine. The lateral orientation for the fuel nozzleassemblies, improves cut-to-cup interaction, which can permit reductionof cup count, reducing engine complexity and weight.

In this way, it should be appreciated that the examples used herein arenot limited specifically as shown, and a person having skill in the artshould appreciate that aspects from one or more of the examples can beintermixed and/or combined with one or more aspect from other examplesto define examples that can differ from the examples as shown. Forexample, the openings arrangement of FIG. 15 can be applied in an angledorientation as shown in FIG. 10 , while all combinations arecontemplated disclosed herein are.

This written description uses examples to disclose the presentdisclosure, including the best mode, and also to enable any personskilled in the art to practice the disclosure, including making andusing any devices or systems and performing any incorporated methods.The patentable scope of the disclosure is defined by the claims, and mayinclude other examples that occur to those skilled in the art. Suchother examples are intended to be within the scope of the claims if theyinclude structural elements that do not differ from the literal languageof the claims, or if they include equivalent structural elements withinsubstantial differences from the literal languages of the claims.

Further aspects are provided by the subject matter of the followingclauses: a turbine engine comprising: a compressor section, combustorsection, and turbine section in serial flow arrangement, with thecombustor section defining a longitudinal axis, and having a fuel nozzleassembly, the fuel nozzle assembly comprising: a fuel nozzle defining alongitudinal axis, a lateral axis, and a transverse axis perpendicularto the lateral axis, and including a nozzle cap; and a set of fuelopenings provided in the nozzle cap collectively defining a total area,wherein the set of fuel openings are arranged in the nozzle cap suchthat a greater amount of the total area is distributed closer to thelateral axis than the transverse axis.

The turbine engine of any preceding clause, wherein at least one fuelopening of the set of fuel openings is elliptical with a major axisdefined along the lateral axis.

The turbine engine of any preceding clause, wherein at least some fuelopenings of the set of fuel openings are arranged as radially outer fuelopenings relative to a radius extending from the longitudinal axis.

The turbine engine of any preceding clause, wherein at least some fuelopenings of the set of fuel openings are arranged as radially inner fuelopenings.

The turbine engine of any preceding clause, wherein the set of fuelopenings further includes a central fuel opening and the central fuelopening is circular.

The turbine engine of any preceding clause, wherein at least some fuelopenings of the radially outer fuel openings are different sizes thanother fuel openings of the radially outer fuel openings, and wherein asize of the radially outer fuel openings increases in a directionextending along the lateral axis.

The turbine engine of any preceding clause, wherein at least one fuelopening of the set of fuel openings is elliptical with a major axisdefined parallel to the transverse axis.

The turbine engine of any preceding clause, wherein the fuel nozzle isone of a set of fuel nozzles, where at least some fuel nozzles of theset of fuel nozzles are circumferentially offset from other fuel nozzlesof the set of fuel nozzles defined in circumference relative to a radialdirection perpendicular to the longitudinal axis.

The turbine engine of any preceding clause, wherein the fuel nozzleincludes a set of fuel nozzles, where at least some fuel nozzles of theset of fuel nozzles are arranged at an angular offset, wherein thelateral axis is arranged at the angular offset relative to a tangentialaxis arranged tangent to a radial direction perpendicular to thelongitudinal axis.

The turbine engine of any preceding clause, wherein the at least somefuel nozzles of the set of fuel nozzles arranged at the angular offsetincludes every other fuel nozzle of the set of fuel nozzles.

A fuel nozzle assembly comprising: a fuel nozzle, defining longitudinalaxis, including a fuel passage terminating at a nozzle tip; and a capprovided in the fuel passage and including a set of openings, the capdefining a lateral axis and a transverse axis perpendicular to thelateral axis, wherein the cap defines a total area, and the cap isshaped such that a greater amount of the total area is distributedcloser to the lateral axis than the transverse axis.

The fuel nozzle assembly of any preceding clause, further comprising aswirler circumscribing the fuel nozzle and defining a swirler passagebetween the swirler and the fuel nozzle, and wherein a swirler passagearea is defined between the swirler and the fuel nozzle in a directionparallel to the lateral axis and the transverse axis, and a greateramount of the swirler passage area is distributed closer to thetransverse axis.

The fuel nozzle assembly of any preceding clause, wherein the fuelnozzle further comprises an outer wall with a wall thickness, andwherein the wall thickness is greater along the lateral axis andrelatively less along the transverse axis.

The fuel nozzle assembly of any preceding clause, wherein at least someopenings of the set of openings are different sizes than other openingsof the set of openings.

The fuel nozzle assembly of any preceding clause, wherein the set ofopenings increase in size in a direction extending along the lateralaxis away from the transverse axis.

The fuel nozzle assembly of any preceding clause, wherein the set ofopenings further include radially inner openings and radially outeropenings, and wherein the radially outer openings are arranged in anelliptical pattern.

The fuel nozzle assembly of any preceding clause, wherein the set ofopenings further includes at least one radially center opening arrangedradially within both the radially outer openings and the radially inneropenings.

A method of injecting fuel from a fuel nozzle assembly including a fuelnozzle and defining a lateral axis and a transverse axis, the methodcomprising: injecting a volume of fuel through a set of openings in anozzle cap provided in the fuel nozzle; and spreading a greater amountof fuel in a direction along the lateral axis, and a relatively lesseramount of fuel in a direction along the transverse axis.

The method of any preceding clause, wherein the nozzle cap includes anon-circular shape configured to spread the greater amount of fuel inthe direction along the lateral axis.

The method of any preceding clause, wherein the set of openings arearranged in an elliptical pattern defining a major axis along thelateral axis.

What is claimed is:
 1. A turbine engine comprising: a compressorsection, combustor section, and turbine section in serial flowarrangement, with the combustor section defining an axis, and having afuel nozzle assembly, the fuel nozzle assembly comprising: a fuel nozzledefining a longitudinal axis, a lateral axis, and a transverse axisperpendicular to the lateral axis, and including a nozzle cap; and a setof fuel openings provided in the nozzle cap collectively defining atotal area, wherein the set of fuel openings are arranged in the nozzlecap such that a greater amount of the total area is distributed closerto the lateral axis than the transverse axis.
 2. The turbine engine ofclaim 1 wherein at least one fuel opening of the set of fuel openings iselliptical with a major axis defined along the lateral axis.
 3. Theturbine engine of claim 1 wherein at least some fuel openings of the setof fuel openings are arranged as radially outer fuel openings relativeto a radius extending from the longitudinal axis.
 4. The turbine engineof claim 3 wherein at least some fuel openings of the set of fuelopenings are arranged as radially inner fuel openings.
 5. The turbineengine of claim 4 wherein the set of fuel openings further includes acentral fuel opening and the central fuel opening is circular.
 6. Theturbine engine of claim 3 wherein at least some fuel openings of theradially outer fuel openings are different sizes than other fuelopenings of the radially outer fuel openings, and wherein a size of theradially outer fuel openings increases in a direction extending alongthe lateral axis.
 7. The turbine engine of claim 1 wherein at least onefuel opening of the set of fuel openings is elliptical with a major axisdefined parallel to the transverse axis.
 8. The turbine engine of claim1 wherein the fuel nozzle is one of a set of fuel nozzles, where atleast some fuel nozzles of the set of fuel nozzles are circumferentiallyoffset from other fuel nozzles of the set of fuel nozzles defined incircumference relative to a radial direction perpendicular to thelongitudinal axis.
 9. The turbine engine of claim 1 wherein the fuelnozzle is one of a set of fuel nozzles, where at least some fuel nozzlesof the set of fuel nozzles are arranged at an angular offset, whereinthe lateral axis is arranged at the angular offset relative to atangential axis arranged tangent to a radial direction perpendicular tothe longitudinal axis.
 10. The turbine engine of claim 9 wherein the atleast some fuel nozzles of the set of fuel nozzles arranged at theangular offset includes every other fuel nozzle of the set of fuelnozzles.
 11. A fuel nozzle assembly comprising: a fuel nozzle, defininga longitudinal axis, including a fuel passage terminating at a nozzletip; and a cap provided in the fuel passage and including a set ofopenings, the cap defining a lateral axis and a transverse axisperpendicular to the lateral axis, wherein the cap defines a total area,and the cap is shaped such that a greater amount of the total area isdistributed closer to the lateral axis than the transverse axis.
 12. Thefuel nozzle assembly of claim 11 further comprising a swirlercircumscribing the fuel nozzle and defining a swirler passage betweenthe swirler and the fuel nozzle, and wherein a swirler passage area isdefined between the swirler and the fuel nozzle in a direction parallelto the lateral axis and the transverse axis, and a greater amount of theswirler passage area is distributed closer to the transverse axis. 13.The fuel nozzle assembly of claim 11 wherein the fuel nozzle furthercomprises an outer wall with a wall thickness, and wherein the wallthickness is greater along the lateral axis and relatively lesser alongthe transverse axis.
 14. The fuel nozzle assembly of claim 11 wherein atleast some openings of the set of openings are different sizes thanother openings of the set of openings.
 15. The fuel nozzle assembly ofclaim 14 wherein the set of openings increase in size in a directionextending along the lateral axis away from the transverse axis.
 16. Thefuel nozzle assembly of claim 11 wherein the set of openings furtherinclude radially inner openings and radially outer openings, and whereinthe radially outer openings are arranged in an elliptical pattern. 17.The fuel nozzle assembly of claim 16 wherein the set of openings furtherincludes at least one radially center opening arranged radially withinboth the radially outer openings and the radially inner openings.
 18. Amethod of injecting fuel from a fuel nozzle assembly including a fuelnozzle and defining a lateral axis and a transverse axis, the methodcomprising: injecting a volume of fuel through a set of openings in anozzle cap provided in the fuel nozzle; and spreading a greater amountof fuel in a direction along the lateral axis, and a relatively lesseramount of fuel in a direction along the transverse axis.
 19. The methodof claim 18 wherein the nozzle cap includes a non-circular shapeconfigured to spread the greater amount of fuel in the direction alongthe lateral axis.
 20. The method of claim 18 wherein the set of openingsare arranged in an elliptical pattern defining a major axis along thelateral axis.